AMERICAN BATS — ^HANDLEY 193 



Dalquest (1947, p. 20) suggested that this intergrading population 

 probably developed intermediate characters in response to the nature 

 of its environment — intermediate between the humid, forested coast 

 and the arid, treeless deserts, and further postulated that genetic 

 intergradation was not necessarily implied. If this were not an 

 intergrading population I would expect to find constant adaptive 

 characters developed in some portion of its geographic range. How- 

 ever, in examining specimens from all portions of the range assigned to 

 'Hntermedius," I have failed to find such a condition. 



A series of 25 specimens from Mission San Jose, Alameda County, 

 Calif., when arranged in order from pale to dark, quite effectively 

 bridges the color gap between pallescens and townsendii; the average 

 is nearest townsendii. Among 14 specimens from Tulare County, 

 Calif., are three as pale as pallescens, two as dark as townsendii (al- 

 though more reddish), and nine that are intermediate; the average is 

 nearest pallescens. In a series of 16 specimens from Pyramid Lake, 

 Nev., the palest individuals are indistinguishable from tj^pical palles- 

 cens, while the darkest, without reservation, could be called townsendii; 

 the average is nearest pallescens. Six of seven from Malheur County, 

 Oreg., are indistinguishable from typical pallescens, while one is inter- 

 mediate but nearer pallescens. In a series of three specimens from 

 Boulder Cave, Kjttitas County, Wash., one is as dark as typical 

 tovmsendii, while the others are somewhat paler, but nevertheless 

 nearer townsendii. Whitlow and Hall (1933, p. 246) regarded a large 

 series from the PocateUo Region of Idaho as intermediate. 



Similarly, there is intergradation between pale-colored and dark- 

 colored populations in cranial characteristics. This is best seen in the 

 relative stoutness of the rostrum (normally stout in dark-colored 

 northwestern coast populations, normally less stout in pale-colored 

 interior populations). Within the zone of intergradation, stoutness 

 of the rostrum can not be correlated with coloration: Some pale- 

 colored individuals have the rostrum very stout; some dark-colored 

 individuals have the rostrum rather frail. 



From the specimens and information available to me, it does not 

 appear that there is a population with constant morphological char- 

 acters that could justifiablj^ bear the name "intermedins.^' The fact 

 that intergradation between P. t. townsendii and P. t. pallescens occurs 

 over an extensive geographic area does not make the application of 

 the name " intermedins" to the intermediate population more valid. 

 The ideal in mammalian systematics is to avoid application of special 

 names to geographically and genetically intermediate populations. 

 The use of the name "intermedius" is clearly in violation of this prin- 

 ciple, and the name is best relegated to synonymy. 



